vance in the applications of machinery to mining would render the work
out of date, and it was at length abandoned.

At about this time Ericsson seems to have taken up seriously his work on
his so-called "flame-engine," certain experiments made by his father
having suggested to him the hope that a source of power might in this
way be developed which would be more economical than the steam-engine.
At this point we see entering into Ericsson's life an idea which never
left him, which controlled much of his work in mid-life, and which
attracted no small part of his attention throughout his closing years.
This idea was the discovery of some form of heat-engine which should be
more economical than the steam-engine, especially as it was in his day.
The flame-engine idea grew rapidly, and soon absorbed his chief
attention. Military life now lost its attraction, and in 1826 obtaining
leave of absence he left his native land and turned his face toward
London, doubtless with the hope strong within him that a substitute for
the steam-engine had been found, and that his future lay secure and easy
before him.

The characteristic features of Ericsson's life up to this time, when he
had reached his twenty-third year, are energy, industry, independence,
all in most pronounced degree, and combined with a most astonishing
insight into mechanical and scientific questions. It was not a period of
achievement, but one of formation and of development in those qualities
which were soon to make him famous in both worlds. Of his work during
this period of life little or nothing outside the idea embodied in the
flame-engine can be said to belong to the permanent record of his life's
achievement. This appeared in the "Caloric" engine, and still later in
the well-known Ericsson "Air" engine of the present day.

This era was one of development and promise, and richly were the
promises fulfilled in the achievements of his later years. A careful
study of his life to this point is sufficient to show that, with health
and time, such a nature would certainly leave a mark wide and deep on
the world in which it was placed. His characteristics were such that
achievement was the very essence of life, and, with the promise and
potency as revealed in this first twenty-three years of his life, we may
be well prepared for the brilliant record of the remaining sixty-three.

With Ericsson's arrival in London began the second important period of
his life. His fi